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Oberon Simulation
This is a simulation of what one would expect to find on a terraformed Oberon, using formulas from Math And Terraforming. Please note that not even the supercomputers at NASA can provide us with a perfect simulation. The information showed here is only an approximation. Basic data *Distance from Sun: 2875.04 million km *Distance from Uranus: 0.583 million km *Diameter: 1523 km *Solar Constant: 0.00535 *Mass: 0.0005046 Earths *Mean density: 1.63 kg/l *Uranus's period: 29.457 Earth years *Day length: 13.643 Earth days *Rotation axial tilt: 98 degrees (82 degrees, retrograde) Atmosphere See Atmosphere Parameters Given the very low gravity, it will be difficult for Oberon to hold an atmosphere. During this simulation, we will use an atmosphere with the same pressure at sea level as Earth's and a similar composition. *Atmosphere stability for oxygen molecules: **Earth's gravity (15 degrees C): 4.116 **Oberon's gravity (15 degrees C): 63.34 **Oberon's gravity (-175 degrees C): 21.58 *Atmosphere stability for water molecules: **Earth's gravity (15 degrees C): 7.320 **Oberon's gravity (15 degrees C): 112.6 **Oberon's gravity (-175 degrees C): 38.36 *Atmosphere stability for hydrogen molecules: **Earth's gravity (15 degrees C): 65.88 **Oberon's gravity (15 degrees C): 1013 **Oberon's gravity (-175 degrees C): 345.2 notes: A value below 10 means stability for over a million years, a value between 10 and 100 means stability between 0.1 and 10 millions of years, while a value higher then 100 means stability for less then 10 thousand years. This calculation does not include solar wind erosion. Conclusion: The atmosphere of Oberon will be divided in two distinct layers, separated by a greenhouse gas buffer. In the upper layer, where temperature will be low, oxygen and nitrogen can be held for thousands of years. However, water vapors, if they make their way that far, will be lost into space. In the lower layer, even oxygen is nearly unstable. Water vapors will fast rise to the upper layer. Hydrogen, resulting from interaction between water molecules and ionizing radiation, will escape into space very fast. The atmosphere will look like this: Ground average temperature: 15 degrees C *Surface pressure at sea level: 1 *Atmosphere total mass (Earth = 1): 0.77 *Atmosphere breathable height: 316 km *Atmosphere total height: 940 km Ground average temperature: -175 degrees C *Surface pressure at sea level: 1 *Atmosphere total mass (Earth = 1): 0.42 *Atmosphere breathable height: 197 km *Atmosphere total height: 586 km Combined values *Atmosphere total mass (Earth = 1): 0.60 *Atmosphere breathable height: 260 km *Atmosphere total height: 750 km. As one can see, Oberon will have an atmosphere that extends a bit above its radius above the surface. At that height, gravity is reduced to half, forcing in fact the atmosphere to be even higher. If Oberon will one day be terraformed, the atmosphere will lack stability and will slowly be lost in space. Still, for at least a thousand years, it will remain as it is. Temperature Main article: Temperature. The first problem with Oberon is that we need to gain the correct surface temperature. The Solar Constant is small (0.00535), compared to Earth (1.98). We will need Greenhouse Gases. The Greenhouse Calculator shows us that Titan will need 2.68 kg/sqm of sulfur hexafluoride. Climate Simulation Main article: Climate. On Earth, the average temperature is +15 degrees C. Technicians will try, with the help of greenhouse gases, to keep this temperature. Oberon has a smaller diameter then Earth (0.119), so air currents can mix temperatures faster. The atmosphere will be high enough to pass over all Geographic barriers. Average temperatures for each latitude: At equinox: *poles: 14.3 C *75 deg: 14.8 C *60 deg: 15.0 C *45 deg: 15.2 C *30 deg: 15.3 C *15 deg: 15.4 C *equator: 15.5 C At winter solstice: *poles: 14.6 C *75 deg: 14.7 C *60 deg: 14.7 C *45 deg: 14.8 C *30 deg: 14.9 C *15 deg: 15.0 C *equator: 15.0 C At summer solstice: *poles: 15.5 C *75 deg: 15.5 C *60 deg: 15.4 C *45 deg: 15.2 C *30 deg: 15.1 C *15 deg: 15.1 C *equator: 15.0 C Day - night cycle variation: Oberon has a relatively day (4.518 Earth days), but is well protected by its greenhouse layer. So, temperature variations between day and night will not be significant. *Daily temperature variation: 0.5 degrees C *Equator day-night variations: **Equinox: 15.3 to 15.7 degrees C **Solstice: 14.8 to 15.2 degrees C *Day - night variations for 45 deg latitude: **Equinox: 15.0 to 15.4 degrees C **Winter solstice: polar night, no variation **Summer solstice: polar day, no variation Seasons: Uranus has the most tilted axis in the Solar System, shared by all its inner moons. Because of the extremely long uranian year, one hemisphere will be covered in darkness for a long time, while the other hemisphere will experience a long polar day. However, because of the strong greenhouse effect needed, the moon will not experience temperature changes. At the poles, differences will be about one degree C. Altitude variations: Given the fluffy atmosphere that will be created, pressure will not decrease significantly. A mountain 31.5 km high on Oberon will experience a temperature change like a mountain that is 1 km high on Earth. So, temperature variations caused by altitude should be ignored. Conclusion. Oberon will experience a climate pattern known as monoclime, with very small temperature variations. In such conditions, winds will be very slow, but highly predictable. They will exchange temperatures between hemispheres. With little temperature variations, the atmosphere will get saturated with moisture. It will be a very wet climate, with many hazes and clouds. Still, because temperature will not drop significantly, it will not rain much. Still, Oberon has an advantage, that can bring some climate changes from time to time. Above the greenhouse gas layer, during long polar nights, the atmosphere will condense and will start to snow. When this will happen, it will bring a significant decrease of temperature, that will stimulate winds to form. This phenomena can decrease temperature significantly, forcing the clouds to rain. Then, cooled air will move to the illuminated hemisphere, where it will heat-up, absorbing moisture. This phenomena can produce a few days of clear blue sky. After this, the moon will gradually heat-up back to its stability temperature value. Geography See also: Geography and Geographic Pattern - Craters. It appears that Oberon contains about half water ice and half other materials. We don't know well if the moon is differentiated into an icy mantle and a rocky core. Oberon might once had a subsurface ocean, but now it must be completely frozen. Terraformers have 4 major ways to transform an icy Outer Planet: #Increase the heat, melt the ice and transform it into an Oceanic Planet, then leave it as it is. #If possible, build Artificial Continents after melting all the ice. #Use Ground Insulation, to save the icy crust, then cover it with solid rock. # Heat the moon, until solid particles from the molten ice will form a natural insulation above the ice crust (see Iapetus Simulation). The first option, without an added source of heat, will take us a lot of time. at Uranus's distance, solar radiation is weak. The ice will melt with an average speed of 3.9 mm melt daily and 1.38 meters melt in an Earth year (see Adjusting Temperature for details). It will take us 72500 years to melt the ice down to 100 km. Still, if we manage to heat the moon somehow, then the ice will completely melt and we will have an oceanic world. Then, it is possible to build artificial continents. The third option, that of using ground insulation, might be possible using materials that already exist on the moon. However, it is costly, even if far less costly then the heating of all ice. The fourth option is also possible. If we use a source of heat, to melt the ice down to 200 m, then debris kept in the ice will form a layer of ground that might be 20 to 50 m thick. This insulation layer will reduce ice melting speed significantly. And because the icy crust is very cold (and will remain cold for a long time), it is expected that, at least for a few thousand years, water will freeze at the bottom of the insulation layer. Depending on what method we will use, the moon will look completely different. 1. Oceanic planet: In this scenario, Oberon will have a very deep, global ocean, with no island. Manmade floating islands can exist, still. The ocean, because of the lack of winds, will have only very small waves. Water will help mix temperatures. 2. Artificial continents: In this scenario, there will be large floating islands. Because the ocean is expected to lack powerful currents, continents will remain to their positions for a long time. To save budget, it is expected that continental crust will not be thick. So, high mountains will not exist. 3. Ground insulation: In this scenario, the moon will be covered with a global protective layer, that will insulate the ice for millennia. Many Geographic features will be altered (mountains excavated, craters filled), so the resulting terrains will be different. Probably, oceans will cover 50% of the surface. 4. Natural ground insulation: This option, the cheapest of all, will create erosion valleys on the surface and depressions filled with sediments. Water, being heavier then ice, will sink through holes and pores into the moon, freezing at a certain depth. Almost all Geographic features will be preserved. Ground will be covered with black soil. There will be no or almost no lakes. Conclusion: Terraforming Oberon has different approaches, each one with different results on the moon and all its Geographic features. Unfortunately, Oberon was visited only once by a spaceship. We don't have altitude maps and over half of the surface was never imagined in high detail. The Sky As any Outer Planet, Oberon will have a lot of moisture in its atmosphere. The blue sky will be visible on rare occasions, that will probably be holidays on the surface. Still, from orbit, some celestial bodies will be visible. The Sun will appear 0.48 units wide (like an object 0.48 mm wide will appear if you look from a distance of 1 m, see Angular Size for details). Uranus and other satellites visible as disks will be: *Uranus - 87 units *Miranda - 0.66 to 1.04 units *Ariel - 1.75 to 3.45 units *Umbriel - 1.44 to 3.27 units *Titania - 1.55 to 10.72 units. Some planets will also be visible, with a Magnitude as follows: *Mercury: 6.2 to 6.3 *Venus: 3.3 to 3.5 *Earth: 4.5 to 4.8 *Mars: 5.9 to >6 *Jupiter: 2.3 to 3.5 *Saturn: 2.9 to 5.3 Please note that values are calculating assuming that a planet is visible as a full moon and not as a crescent. Inner planets will only be seen as crescents, so their visible magnitude will always be with about one unit higher. So, Mercury and Mars will actually not be visible. On the other hand, a planet that is too close to a source of light like the Sun will actually not be visible. Because of this, only Jupiter and Saturn could be seen with the naked eye. Human Colonies *Population limit: 190 000 *Land population feeding capacity: 0.9 people fed from one square km *Largest city supported by environment: 760 people Assuming it will have similar types of terrain Earth will have, Rhea can support a Population Limit of 190 000 people. An outer planet, with a very strong greenhouse effect, will be in delicate balance. It will be required only little human activities to boost its temperature into a runaway greenhouse effect, losing the atmosphere. Industry It is not known what kind of industry will Oberon be able to support. The moon is made mostly of ice and does not contain significant resources. Industrial centers will have to import most of their primary materials. The only source of energy appears to be nuclear. Agriculture With very little illumination, it will be very hard for plants (see Plants on new worlds for details). People will have to grow plants using artificial light. Transportation With a very small population, building massive infrastructure will not be feasible. More likely, people will use airplanes, taking advantage of the weak gravity. Since Oberon is tidal locked, there is no place for geosynchronous satellites. Still, there are many safe orbits around the moon for satellites that will provide telecommunications. The large atmosphere will pose major challenges for radio waves. There will be constructed at least one base on the surface, for space travel. Large interplanetary ships, carrying passengers and cargo to and from Saturn, will dock at Perdita. Then, smaller ships will ferry between the little moon Helene and Oberon. Tourism It is questionable what kind of tourism can exist on Oberon. Its wet climate will be unpleasant. Wild Life The major problem for plants is the lack of light. Oberon will be a place where Earth plants adapted for darkness (for example those on the floor of a dense forest or at the entrance in a cave) will live in exposed air. Forests might exist, but on the forest floor no plant will survive. With little light, plants will have a very small productivity. Because of this, animals will be in small numbers. Because of the highly tilted axis, each hemisphere will be engulfed in darkness for many years. Still, because temperature will be around 15 C, plants will try to grow, to reach a source of light. The direct result is that plants will die. Life will survive around the equator. During polar days, plants and animals will try to conquer each hemisphere, but during polar night, they will die or return to the equator. Category:Simulation Category:Math